Electric-motor drive.



C. C. BATCHELDER, ELECTRIC MOTR DRIVE.

APPLIQATION FILED JUNE 23,1909.

Patented Oct. 14, 1913.

M/JITNESSEa NVENTUH m CHARLES C B1/55515175112 u, .Sm

C` C. BATCHELDER.

ELECTRIC MOTOR DRIVE,

PPLICATIQS FILED JUH'223-1909.

UNITED STATES 'ea'irgNT OFFICE.

CHARLES C. BATCHELDEB. OF SCHFENC'I'ADY. NEW YORK, ASSIGNOB GENERLECTRIC COMPANY, A COBPORATION OF NEW YORK.

ELiiiRic-Mo'ron DRIVE.

To all 11:71am, if may concer/z Be it knoivn that l, CHARLES C.Bxrciiei.- una, a citizen of the United States, residing at Schenectady.county of Schenectady, State of New York, have invented certain new anduseful improvements in Electric Motor Drives, of which the following isa specification.

My invention'relates to electric motor,

drives and more particularlyto siich drives for machines composed ofparts each of.

parts of the machine at the proper speed.

to prevent' the sheet from breaking or sag ging betweenthe variousparts. As the paper passes' through the different sections of themachine, it stretches or contracts in theditferent parts of the machineaccording to the grade of paper, and consequently cach part of themachine must be driven atl a slightly different speed from another part,and when thc machine is once adjusted, the speeds of` the diterent partsmust bear a lixed relation to each otlier. In order to accomplish this,I provide each partbf the machine with a separateelectric motor, andfrequency changers connected between the several motors and alternatingcurrent busses, .the speed of the several frequency changers beingindependently adjustable.

For a better understanding of my invention- Areference may be had to thefollowing .descriptiontaken in connection with the accompanying drawingsin which- Figure l shows diagrammatically a paper machine provided withan electric drive in accordance with my invention and in which therevolving members of thev frequency changers are driven by the motorsdriving the Separate parts of the paper machine, and

Fig. 2 shows nmoditied'embodiment of my 'Specification vof LettersPatent.

a fixed-relation to each other, as for instance paper making machines.

A Patented Oct. 14, 1913. Application med Jme 23, isos. seriai No.503.7'90. i

invention in which the revolving members of the frequency changers haveindependent" motors for driving'them.

Referring to the drawings, A, z-and fAs are'thearmatures of the motorsdriving the various parts, B1, B2 and Ba ofv amachine,

each at a slightlydifferent'speed from an.

other. These motors are shown as beingv of the direct-en ril'entt.peivith alternatiiificur.v rentconnections,w ichma revolvin arm! attireymachine Aas shown, comprise co lectorA` Y rings .tap ed to suitable""oi'nts' oftlie armature 'win iig. The speed) may be controlled inf any,suitable manner, as for example, by tlyiewell knownfiwaid Leonar systemi'n which the's eedof the ofthe machine` as A a' \\'hole,vthat is, thespeed of. all the motors motors is controlled-by viiying t e value of lthe electromot'ive' force ofthe generator C, supplving the armatures ofthe 'motors .if and A, The field win-dings fl, f and f of the motorsareseparatelyexcited" b'y'tlie .Uenerator D, which alsosup'plies thecita.- 'tion for generator C. The induction frequency changers El; E.andE are connected bctiveen the motors, and the Aalternatingcurrentbusses L, L2 and L3'. A\s shown, the collector rings of the armaturesA1, A and A are connected to the stmtionary members of the frequencychangers, the revolving members being connected to `the busses L1., L'j'and 11";

In Fig. 1t'h'e revolving membei-of eacl .frequency changer is driven'from its corresponding motor by means of a variable `pt-ed mechanism ofany suitable design. As shown in the drawing` the variable speedmechanismsconsist of the disks F1, F2 and l mounted on the shafts'of thearmatures .V and A3 respectively, which disks frictioiially engage thedisks G2 and G- tion, while the disks l1"1 and G engage so as to drivethe revolving member of the frequency changer E3 in the oppositedirection,

are supplied with 'current from the generator C. The relative speeds ofthe different revolving` members may be changed` by means ofA rheostatsK1, K2 and K3 in series -with the armatures of the motors Il, I2 and I3and the reversing switches M, M2 and M3- Asshown in this figure of thedrawings, the reversing'switch Mx is in a posibers of the frequencychangers are held sta-4 tion such that the motor Il runs in onedirection, while the reversing switch vMa is in a position such that themotor I3 runs in the opposite direction, and motor I1 is open``circuit'ed at the rheostat K, s0'that:it is stationary. i

The frequency changers are held stationary when the speed changingImechanism in Fig. 1 is in the position in w ich there is no tendency torevolve the frequency changers,

or the motors for driving the revolving members of the frequencychangers in Fig. 2 are open-circuit'ed. If the rotatable metilber of aninduction frequency changer"is held stationary, the frequency of thecurrent in both members is the same, and the frequenc changer will.operate as a stationary `trans ormer.- I f the rotatable member hasimpressedzlu'pon it a voltage of a definite frequency and is revolvedinfa backward direction, that is, against the mechanical forcev actingbetweeri the members, the frequency in the stationary member. is equalto the'surn of the requene of rotation of the revolving member an theiinpressed frequency on the revolving member, while if it is revolvedin'. a forward direction the frequency in the stationary member is equalto the difference between the impressed frequency and the frequency bfrotation.

It 1s well known that if direct-current motors are supplied withcollector. rings, which are connected-toget ier either directly orthrough stationarytransformers to busses, the motors will be compelledto run in synehronism, as is clearly explained in the'patent to Thomsonand Rice, 545,111,"dated August 27, 1895. If all the rotatablememtionary, they act as stationary transformers, so that all thearmatures A1, A2, andl A areheld in synchronism. --.If the disk F1rotate thernotor I* as shown in lfig. 2, that "is, sor-that therotatablemember.' of frcquencv changer Ex is rotated backward, a

member slightly greater than the' frcqmnc)Y l of thc current in thebusses L1, l.c and L". Since. the stationair-5l member of frequencychanger lil is connected to the collector rings of armature crosscurrent will flow bctu-'ecn the two machines,v speeding up armatureuntil it is in synchronisn'i with tho current of' increased frequency.The speeding up of armature-.\l requires power which is supplied by thefrcqucncy'changer. 'jhe field of the direct-current motorA may then beadjusted so that the power for maintaining this increased speed will hetaken from the generator C. lf the disk F 3 is shifted so as to engagethc disk Gf as shown in F ig. 1, or thereversing switch Ma-nd rheostat Kare adjustedtofrotate the motor rotatable member-fof.'frequeneyiolian'ger E?.

.13, as shown inv Fig. 2,` that is, so that the rotated forward,- afrequency is v rod u'c'e 1 f` .1n the vstationary member1sligh tly essthan tion to each` other due to the synchronizing v connectionsthrough-.fthe frequency changers,

the revolving members.of whichare connected together to thesamegbusses.

I desirenitfto be understoodthatnmyinvention is 'not limited'fto theparticularembodifnents shown and andI aim.

in the ap cations w ich do not depart .from the spirit and 'scope of myinventions-ii' i What I claim as new anddesire to secure by LettersPatent of Ithe-"United States, 1s:

1. In combination, a pluralityof motors,

a set of alternating-current busses, frequencv changers connectedllncircuit between sal ndedl claims td'eover allniodibusses and saidmotors, and means for driv-f mg said frequency changersvfrom'saidmotors-'at slightly different relative speeds.

2. Imeombination, a lurality of directcurrent motors adapte rect-currentsupplying "said motors, a set of alternating-current busses,' frequencychangers connected between said busses and' to loe-driven at slight-lydifferent speeds andhaving alterhating :current connections, a source ofdi-.

said motors, amb-means wherebygsaid.fre-v qucncy changers may be drivenat slightly 'different relative speeds.

3. In combinatioma lurality of directcnrrent motors adapte to be drivenat slightly different speeds and having alternating-currcnt connections,a. source of direct-current supplying said motors,`a set ofalternating-current busses, frequency changers connected between saidbusses and said motors, and means for driving said frequency changersfrom said direct-current motors at slightly different relative speeds.

4. In comblnation, a plurality of motors, a set of alternating-currentbusses, frequency changers connected in circuit between said busses andsaid motors, and variable speed mechanisms for driving said fre4 quencychangers from said motors either in a forward or a backward direction.

5. In combination, a lurality of directcurrent motors adapted) to bedriven at slightly differentspeeds and having alternating-currentconnections, a source of direct-current supplying said motors, a set ofalternating-current busses, frequency changers connected between saidbusses and said motors, and means whereby said frequency chan ers may bedriven either in a forward or a ckward direction.

6. In combination, a lurality of directcurrent motors ada to be drivenat slightly different speeds and having altermating-current connections,a source rect-currentl supplying said motors, a set ofaltemating-current busses, frequency changers connected between saidbusses and said motors, and variable speed mechanisms for driving saidfrequency changers from said motors either in a forward or a. back warddirection.

In witness whereof, I have hereunto set my hand this 21st day of June,1909.

CHARLES C. BATCHELDEB Witnesses:

BENJAMIN B. HULL, HELEN Oaronn.

